For an electronic device using radio frequency of large power, it is important to effectively discharge heat radiated from the amplifier, etc.
For this, it is proposed to provide a metal member in an opening formed in the substrate and provide an amplifier, etc. on the metal member, whereby the heat radiated from the amplifier, etc. is effectively discharged.
Related references are as follows:    Japanese Laid-open Patent Publication No. 2003-179181; and    Japanese Laid-open Patent Publication No. Hei 10-242377.